Securing means



Sept. 27, 1949,

P. G. FRERER SECURING MEANS Filed May 7, 1946 PAUL e FRERER Patented Sept. 27 1949 SECURING MEANS Paul G. Frerer, Baltimore,..Md., assignor to Ben dix Aviation Corporatiom'Baltimorc, Md., a

corporation of Delaware Application May '1, 1946, Serial No. 667,858 I 7 Claims. (01. 292 -137) This invention relates to protective housings and more particularly to such a housing of a type which may be disassembled using relatively simple apparatus but yet may not be disasssembled at all by those unfamiliar with its design without destruction of same.

This application is a continuation in part of my copending application, Serial No. 658,602, filed April 1, 1946. As is well known, many complex and delicate pieces of equipment are now placed at the disposal of lay persons to control apparatus, to perform measuring operations, and to render other valuable services. Inasmuch as this apparatus is normally employed by people who are relatively unfamiliar with the mode and manner of its operation and who lack the fundamental knowledge necessary for its adjustment and maintenance, it becomes desirable to prevent access by others than those who have been properly initiated in such knowledge. While rendering the interior of such units inaccessible to those who are not possessed of the special knowledge required, yet the mode of so rendering the interior of the unit inaccessible must be such that it re quires little or no additional effort on the part of skilled personnel than would the releasing of more conventional closures.

Accordingly it is a principal object of the invention to provide a new and novel enclosed assembly, the method of opening which is not immediately obvious upon inspection.

Another object of the invention is to provide a new and novel enclosure assembly of a type openable only by those with special knowledge in which the opening may be performed with simple inexpensive tools. e

A further object of the invention is to provide a base and cover assembly in which the interrelation of apertures traversing the base affords provision for an unobvious release of the housing from the base.

Other objects and advantages of the invention will in part be obvious and in part be disclosed when the following specification is read in conjunction with the drawings in which;

Figure 1 is a side elevation, partly in section, illustrating the base and housing in a closed relationship.

Figure 2 is a view in elevation, partly in section, illustrating the base and housing with the closure pin driven into the'release position.

Figure 3 is a bottom view of the base assembly illustrating the relative aperture orientation.

Figure 4 is a view in elevation partly in section sition with the closure pin available for removal and Figure 5 is an end view showing the base and cover of the assembly indisassembled relationship.

Referring now to the drawings, there is shown a base i 0 upon which is mounted a cover l2. The apparatus in conjunction with which the principles of the invention are here illustrated may be an electric switch, such as that shown in my aforementioned co-pending application entitled Snap acting contactor; mounted on the base Ill. While closures of this nature are particularly advantageous in connection with such switches, whose calibration and continuity of operation depend upon delicate adjustments which must not be-tampered with by the uninitiated, it is understood that this'particular combination has been selected for illustrative purposes only and is not to be construed as limiting the scope of the invention which isdirected to closures generally.

As-is more completely obvious from the aforementioned co-pending application a snap switch assembly, as indicated generally by reference character I4, is mounted on the base Ill and protected from ambient atmospheric conditions by the surrounding cover [2 secured in place over the snap switch assembly [4. The cover I2 is provided with 'a pair of depending ears It to be seen'mo'st clearly in Figures 4 and 5. The cars l-B project into' a recess I'8 located at each end of the base l0; Each of theears I6 is traversed by an aperture l1 and when the cover I2 is in place upon'the'base ill the cover aperture I1 is in register with acorre'sponding aperture 20 of similar diameter" provided in the base Ill. The aperture 2!! terminates at'the wall of a transverse aperture 22 in the base- H], the point'of termination being the wall of aperture 22 nearest the recess l 8; thus the aperture 20 has an inner extremity and its length is determined by the intersection of its inner extremity "with the wall of aperture 22 nearest recess l8. For reasons which will become more obvious, the diameter of thetransverse aperture 22, measured in a direction parallel to the length of aperture 20, must be at least equal to and preferably somewhat greater than the difference between the length of the pin 24 and the length of aperture 20. After the base mounted unit [4 has been completely calibrated, the cover i2 is slipped into position on the base (0 with the cover lug aperture H in register with the recess apertures 20. The'pin 24, is then driven into the cover aperture and the base aperture 20 until illustrat ng cover and base in a disassembled po- 55. the head thereof is substantially flush with the outer surface of the cover l2. While this provides the neatest assembly, the pin may also be driven in further than this, so long as the head is not driven beyond the inner face of the projecting lug I6, when it would no longer serve its retaining function.

This is the condition in which the completed unit is shipped and placed in seritiee. Should the equipment operate erratically thewrsen-ifitempted to gain access to the interior, will gain no clue as to the sole mode of disassembly without destruction, by examination of the exterior. Thenatural reaction is to attempt to remove pin 2! which cannot conveniently be done; llnmceni t sbecomes most probable that the unit be domarfiedito a service center properly equipped both with tools and knowledge. Upon arrivaliatthe seravieenenter using a proper tool the pin 24 is driven inwardly until the head thereof is flush with or slightly below the inner face of the recess [8. The cover l 2 zmaynawihemeadilyiremoved-and the necessary service operations performed.

Preparatory (to The-assembly lit is necessary to remove the pin 24.. As previously outlined the dimension of the aperture 22, measured parallel to the line of traiiel 20f pin 12!, greater {than :the diffierence between the length of pin 24 :and of aperture 2|?! hence, it dsznot necessary the drive the pin 24 into contact with ithe apposite wall of the aperture 22 'andinipractine iit is only driven so "far as necessary to melsase ithe cover 12 permitting clearance 1120 memain Ybetwesn :the doottom end of pin 24 :and the supposing wail :of :aperture Removal of :pin 2.4 181583121385 Thy forcing :a, tapered plug within the =22 whereupon the pin 26 rides upwardly :and mttwandly son *the tapered surface, until fthe Shea-d itheneof projects beyond the inner slime 53f ime :reuess =18, whencelit:mayheremovedinmonvcntimralmeans. Re-assembly :is BBI'fOImQflEEMQVB indicated.

It is desirable that when dhennit is rcmnpletely assembled, the dimer send ref the 2 4 he mot visible within the bore of the flartersscting aperture since this "would igii e :a sine as to :the mode .01 :disassembly "Ihus ttheflengthaof the ipin 24 should not exceed them of like iength pf aperture '20 and the newer dhzlulmess. lit iszfnrther desirable that the'ilnngth of pin :24 213B ithan the length of aperture 211., :so slzhat when the inner end :of pin :2 .is driven diush with of aperture 22 at :its intersention arperdmre '20., the head of pin 12! will prod-nude zbeyond thelbase of recess I8, 2130 permit removal thereof. As an operative criterion, fit is elem *that the length of the pin 24 must not exceed thersum f the leng-th of aperture 20 andthe rof aperture '22, measured parallel to the diredtion of travel 0f pin 26 withinaperture 213, else :never be possible to disen age the :pin 21 from aperture I to permit removalo'f the cover 1:2

The invention may he ein-bodied in other specific form's without departing from the spirit or essential "characteristics thereof. The present embodiments iare therefore tobe considered all respectsa-s illustrative and not'res'trictive,the scope of the invention being by appended claims rather than by the foregoing description, and all changes which eome within the meaning and of of the claims are therefore intended to be embraced thereby.

What is claimed, and desired to be secured by United States Letters Qatent is:

' -first aperture exceeding the depth of said recess;

.said depending projection having an aperture normally in register with said first aperture; and zaipinlhzwmgalength greater than the depth of said recess and less than the sum of the depth (if "saidrecess and the length of said first aperture situated v,within said projection aperture and within said first base aperture.

:2. in a housing; a cover provided with a depending projection; a lbase adapted to receive said cover and provided with a recess complementary to said projection, with-a first aperture extending :into said base from said irecess and. xhaviingran irmer extremity and within. second aperture disposed transversely of :and intersecting said first aperture at the said .inner extremity, said first aperture terminating at T121516 wall .of .said second :aperture nearest the said recess; said second aperture having a dimension measured'pa-rallel to said first aperture exceeding the depth of said recess; said depending projection .having an aperture normally register said first apentune; and a pinihaying a zlength greater than the depth -,of .said recess, greater than the length of said first a;pertu1te, :and less than the sum of the depth \of .said recess and the length of .said first aperture situated within .said :projeotion aperture and within said rfirst :base aperture.

3. a housing; 'a cover provided :a depending projection having a predetermined thickness; .=a base adapted to receive said cover and provided withza recess complementary to said projection, with :2. first aperture extending into said base from said recess sand having an inner extremity and with a .second aperture id-isposed transversely of and intersecting said first aperture (at the :said inner extremity, said first aperture'terminating ratwthe wall 10f :said second "aperture nearest the said recess; said second aperture having a dimension measured parallel to said fast aperture exceeding said predetermined thickness; said depending projection having an aperture normally in register with said first taperture; anda pinrhaving aflength {greater thanzsaid predetermined thickness and less'than the sum of said predetermined thickness and the length of said .first'apenture {situated within saidproject'ion aperture and said first base aperture.

lln :a housing; :a cover provided with a depending projection having e. predetermined thickness; a' base adapted to receive said cover and-provided with arecess complementary to said projection, with (a aperture extending into said base from :said recess and having an inner extremity and a second :aperture disposed transversely '-:of and intersecting said first aperture at the said inner extremity, said first aperture terminating at the wall of said second aperture nearest the said recess; said second aperture having a dimension measureizl'para'llel to said first aperture exceeding said predetermined thickness; said depending projection having an aperture normally in register with said first aper- 1, I hanging; 3 mm a m t fie.- lfi ture; and a pin havinga length greater thansaid predetermined thickness and less than the sum of the length of said first aperture and said dimension of said second aperture situated within said projection aperture and within said first base aperture.

5. In a housing; a first member forming a partial enclosure and having an aperture extending therethrough; a second member cooperating with said first member to form a complete enclosure and having a first aperture adapted to register with said aperture in said first member when said two members are in cooperating relationship said first aperture having an inner extremity, with a second aperture disposed transversely of and intersecting said first aperture at the said inner extremity, said first aperture terminating at the wall of said second aperture nearest the said recess; and a pin situated within said aperture in said first member and within said first aperture; said second aperture having a dimension measured parallel to said first aperture in said second member greater than the length of said pin minus the length of said first aperture in said second member.

6. In a housing; a first member forming a partial enclosure and having an aperture extending therethrough; a second member cooperating with said first member to form a complete enclosure and having a first aperture adapted to register with said aperture in said first member when said two members are in cooperating relationship said first aperture having an inner extremity, with a second aperture disposed transversely of and intersecting said first aperture at the said inner extremity, said first aperture terminating at the wall of said second aperture nearest the said recess; and a pin of length less than the sum of the length of said aperture in said first member and said first aperture in said second member situated within said aperture in said first member and within said first aperture in said second memher; said second aperture in said second member having a dimension measured parallel to said first aperture in said second member greater than the length of said pin minus the length of said first aperture in said second member.

'7. In a housing, a first member forming a partial enclosure and having an aperture extending therethrough; a second member cooperating with said first member to form a complete enclosure and having a first aperture adapted to register with said aperture in said first member when said two members are in cooperating relationship said first aperture having an inner extremity, with a second aperture disposed transversely of and intersecting said first aperture at the said inner extremity, said first aperture terminating at the wall of said second aperture nearest the said recess; and a pin of length greater than the length of said aperture in said first member and less than the sum of the length of said aperture in said first member and said first aperture in said second member situated within said aperture in said first member and within said first aperture in said second member; said second aperture in said second member having a dimension measured parallel to said first aperture in said second member greater than the length of said pin minus the length of said first aperture in said second member and less than the length of said pm.

PAUL G. FRERER.

REFERENCES CITED The following references are of record in the 

